U.S. patent number 4,742,516 [Application Number 06/817,603] was granted by the patent office on 1988-05-03 for method for transmitting voice information.
This patent grant is currently assigned to Sumitomo Electric Industries, Ltd.. Invention is credited to Mikio Yamaguchi.
United States Patent |
4,742,516 |
Yamaguchi |
May 3, 1988 |
Method for transmitting voice information
Abstract
A system including a broadcasting station which transmits many
independent information packets to many receiving sets in
succession. An information packet consists of a text, a
classification code and a distinction code. Text is a sequence of
words and symbols which may be converted into voice. Classification
codes specify the substance of text, distinction code is annexed to
each different text for distinguishing that type of text from other
texts. A receiving set with registered classification codes selects
and accumulates only necessary information packets by comparing the
transmitted classification codes with stored codes. If the codes
match, the text is stored so that the receiver can playback the
voice information at a convenient later time.
Inventors: |
Yamaguchi; Mikio (Osaka,
JP) |
Assignee: |
Sumitomo Electric Industries,
Ltd. (Osaka, JP)
|
Family
ID: |
26336760 |
Appl.
No.: |
06/817,603 |
Filed: |
January 10, 1986 |
Foreign Application Priority Data
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|
|
|
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Jan 14, 1985 [JP] |
|
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60-3228 |
Jun 13, 1985 [JP] |
|
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60-129018 |
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Current U.S.
Class: |
370/312;
340/7.48; 340/7.55; 340/7.57; 370/349; 370/487; 379/908 |
Current CPC
Class: |
H04H
60/27 (20130101); Y10S 379/908 (20130101) |
Current International
Class: |
H04H
1/00 (20060101); H04J 003/24 (); G08B 005/22 () |
Field of
Search: |
;370/60,94,99
;455/156,158 ;340/825.44,311.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
"Portable computer & host talk over radio-frequency link" by
Jay Krebs-Electronics/Aug. 25, 1983, pp. 142-145..
|
Primary Examiner: Olms; Douglas W.
Assistant Examiner: Scutch, III; Frank M.
Attorney, Agent or Firm: Cushman, Darby & Cushman
Claims
What is claimed is:
1. A method for transmitting information over a system having at
least one broadcasting station and a plurality of receivers,
comprising the steps of:
composing information packets each of which includes a text portion
including a sequence of words and symbols, a classification code
signifying the type of text being transmitted and a distinction
code indicating which of a plurality of repetitions a particular
message is annexed to for each text portion;
converting the information packets into digital signals;
transmitting the digital signals representing said information
packets at least once;
receiving the digital signal information packets at said receivers,
each of which as preprogrammed therein at least one classification
code, the at least one pre-programmed classification code at a
particular receiver being changed, added as a new classification
code or deleted by a user for signifying the type of text the user
wishes to receive at said particular receiver;
selecting received information packets with a classification code
corresponding to the pre-programmed classification code at each
receiver;
selecting the information packets with a distinction code other
than the distinction codes corresponding to already accumulated
text portions so that duplication information is not received;
accumulating the selected information packets; and
conveying to a user information corresponding to the text portions
of the accumulated information packets by at least one of visually
displaying said information and enunciating said information over a
speaker at each receiver.
2. A method according to claim 1 wherein said step of composing
comprises the step of composing information packets having a text
portion where the text comprises sentences including at least one
of the following types of characters: square forms of Japanese
syllabary, alphabets, numerals, Chinese characters, pronunciation
symbols, an accent symbol, a blank symbol, a period and comma.
3. A method according to claim 1 wherein said step of composing
comprises the step of composing information packets having a text
portion where the text comprises sentences including at least one
of the following types of characters: square forms of Japanese
syllabary, alphabets, numbers, an accent symbol, a blank symbol, a
period and a comma.
4. A method according to claim 1 wherein said step composing
comprises the step of composing information packets wherein the
classification code comprises a symbol signifying a classification
code and a sequence of a predetermined number of numerals.
5. A method according to claim 4 wherein said step of composing
comprises the step of composing information packets wherein the
classification code comprises a slash "/" and ten numerals
succeeding the "/".
6. A method according to claim 1 wherein said step of composing
comprises the step of composing information packets wherein the
distinction code comprises a symbol signifying a distinction code
and a sequence of a predetermined number of numerals.
7. A method according to claim 6 wherein said step of composing
comprises the step of composing information packets wherein the
distinction code comprises the symbol signifying a distinction code
and a sequence of ten numerals indicating the year, month, day,
o'clock, and minute of the time of obtaining the text portion of
the information packet.
8. A method according to claim 6 wherein said step of composing
comprises the step of composing information packets wherein the
distinction code comprises the symbol signifying a distinction code
and a sequence of sixteen numerals comprising ten numerals
indicating the year, month, day, o'clock, and minute of the time of
obtaining the text portion of the information packet, two numerals
indicating a repetition number of transmission of the text portion
of an information packet and four numerals indicating the tme of
transmission.
9. A method according to claim 8 wherein said step of composing
comprises the step of composing information packets wherein the
symbol signifying a distinction code is a yen symbol "Y".
10. A method according to claim 1 wherein the step of transmitting
comprises the step of transmitting via electric wire cables.
11. A method according to claim 1 wherein the step of transmitting
comprises the step of transmitting via optical fiber cables.
12. A method according to claim 1 wherein the step of transmitting
comprises the step of modulating a carrier wave with the digital
signals representing said information packets, the binary values
"0" and "1" being represented by the modulation of said carrier
wave with two different frequencies.
13. A method according to claim 1 wherein said step of transmitting
comprises the steps of transmitting by a first broadcasting station
having a wide broadcasting area and transmitting by a second
broadcasting station having a narrow broadcasting area using the
same transmitting medium in turn by time multiplexing the digital
signals representing said information packets for transmission.
14. A method for transmitting voice information from at least one
broadcasting station to a plurality of receivers, comprising the
steps of:
composing information packets each of which includes a text portion
including a sequence of words and symbols and a classification code
signifying a substance of the text portion;
converting the information packets into digital signals;
transmitting one time the information packets substantially as
digital signals via a transmitting medium in succession;
receiving at at least one of said receivers having at least one
classification code stored therein, said transmitted information
packets, said stored classification codes being changed, added as a
new classification code or deleted by a user for signifying the
substance of the text portion the user wishes to receive;
selecting received information packets with a classification code
corresponding to the stored classification code at said at least
one receiver;
accumulating in said at least one receiver selected information
packets having a classification code matching the classification
code previously stored in said receiver; and
conveying to a user information corresponding to the texts of the
accumulated information packets by at least one of visually
displaying said information and enunciating said information over a
speaker at each receiver according to an output order determined by
said at least one receiver.
15. A method according to claim 14 wherein the step of composing
comprises the step of composing information packets wherein said
text portion comprises at least one of the following types of
characters: the square forms of Japanese syllabary, alphabets,
numerals, Chinese character, pronunciation symbols, an accent
symbol, a blank symbol a, period and comma.
16. A method according to claim 14 wherein the step of composing
comprises the step of composing information packets with a
classification code including a symbol signifying that the
following data is part of a classification code, said following
data comprising a sequence of a predetermined number of
numerals.
17. A method according to claim 16 wherein the step of composing
comprises the step of composing information packets wherein said
classification code includes a slash "/" and ten numerals
succeeding said "/".
18. A method according to claim 14 wherein said step of
transmitting comprises the step of transmitting via electric wire
cables.
19. A method according to claim 14 wherein said step of
transmitting comprises the step of transmitting via optical fiber
cables.
20. A method according to claim 14 wherein said step of
transmitting comprises the step of modulating a carrier wave with
the digital signals corresponding to said information packets, the
binary values "0" and "1" being represented by the modulation of
said carrier wave with two different frequencies.
21. A method according to claim 14 wherein said step of
transmitting comprises the steps of transmitting by a first
broadcasting station having a wide broadcasting area and
transmitting by a second broadcasting station having a narrow
broadcasting area by time multiplexing the digital signals
corresponding to said information packets.
22. A method according to claim 1 wherein said step of conveying
comprises the step of synthesizing a voice message from accumulated
text portions.
23. A method according to claim 1 wherein said step of conveying
comprises the step of displaying alpha-numeric characters of said
accumulated text portions.
24. A method according to claim 23 wherein said step of conveying
comprises the step of displaying alpha-numeric characters of said
accumulated text portions.
25. A method according to claim 14 wherein said step of conveying
comprises the step of synthesizing a voice message from accumulated
text portions.
26. A method according to claim 14 wherein said step of conveying
comprises the step of displaying alpha-numeric characters of said
accumulated text portions.
27. A method according to claim 26 wherein said step of conveying
comprises the step of displaying alpha-numeric characters of said
accumulated text portions.
Description
BACKGROUND OF THE INVENTION
This invention relates to a method for transmitting voice
information which enables the transmission of much voice
information with a high efficiency.
Radio broadcasts are popular media for transmitting voice
information to many anonymous people. Radio broadcasting connects
several radio stations with many receivers, with each radio station
monopolizing one frequency of carrier wave. A receiver can select
an arbitrary radio station by tuning his radio dial to the
frequency.
Voices are generated from the receiver's speaker continuously, for
the receiver cannot know the substance of the earlier received
voice information. He or she may miss hearing necessary
information, unless he or she is listening at all times to the
radio. Also, since one radio station sends various kinds of
information, a choice of a broadcasting station is not equivalent
to a choice of the substance of information received. It is the
radio station that determines what kinds of information will be
sent. Consequently, a receiver has the freedom to determine whether
he will hear the radio or not and the freedom to choose a
particular radio station; however, a receiver has no freedom to
determine what substance of information he will hear.
Conventional radio broadcasts also have the following problems:
(1) Nobody can select and hear only the information he or she
requires. For example, a stock price of a certain company in the
stock market cannot be heard at an arbitary time.
(2) A radio receiver set receives an electric wave and converts it
to voice without time delay, time shrinkage or time expansion.
Thus, one must hear the radio in accordance with the broadcasted
program.
(3) One frequency of carrier wave cannot be shared in time (e.g.,
each frequeny being transmitted several tens of seconds) with
plural radio stations, because each radio station must continuously
use its assigned frequency at all times.
SUMMARY OF THE INVENTION
A purpose of the invention is to provide a method for transmitting
voice information which enables a receiver to select and hear only
necessary information.
Another purpose of the invention is to provide a method for
transmitting voice information which enables a receiver to hear the
necessary information at a selected convenient time.
A third purpose of the invention is to provide a method for
transmitting voice information which enables plural broadcasting
stations to use a single frequency of carrier wave in common by
sharing the broadcasting time.
A fourth purpose of the invention is to provide a method for
transmitting voice information which enables much voice information
to be sent to many anonymous people with a restricted transmitting
capacity (e.g., a frequency band of carrier wave).
A fifth purpose of the invention is to provide a method for
transmitting voice information which enables a broadcasting station
to send various types of substantial information.
A sixth purpose of the invention is to provide a method which
enables a receiver to hear his or her necessary information without
fail.
For the above purposes, this invention provides a new method for
connecting a broadcasting station with many receiving sets. The
broadcasting station transmits many "information packets" in
succession, the word "information packet" being used by this
Inventor to designate a packet consisting of a classification code,
a distinction code and a text. The classification code is a code
for classifying the substance of a text. A distinction code is a
code which is annexed to each different text to distinguish each
text, and the text is one or a few short sentences comprising
words, symbols or numerals which represent voice information.
In accordance with the present invention, many kinds of information
packets will be sent. All such information packets are independent
in substance and are sent in succession. It is unimportant whether
an information packet is relevant to the next information packet or
not. Also, unlike radio broadcasts, the transmitted information
packets have no continual substances. A receiver need not hear the
sequences of information packets, for this invention requires no
continuous listening on the receivers' sides.
One information packet may be repeatedly transmitted. At a
receiving set, one or a few classification codes are designated
beforehand. The receiving set thus selects only the information
packets with a classification code which is the same as one of the
designated codes and ignores the other information packets. Also,
in the selected information packets, information packets with a
distinction code which is the same as one of the distinction codes
of the accumulated information packets are abandoned. The receiving
set searches such information packets which have the designated
classification codes and the distinction codes other than that of
preaccumulated ones, and accumulates them into an accumulator. A
receiver thus can hear the necessary voice information by
converting the accumulated texts into voice at some convenient
time.
Three elements of an information packet of the present invention
will be explained.
(i) classification code:
This is a code which signifies the substance of text. Information
to be transmitted relates to weather forecasts, stock market
prices, traffic status, etc. Furthermore, these kinds of
information are subdivided. For example, the weather forecast is
subdivided by districts and times, the stock market prices are
subdivided into stock prices of each corporation and the traffic
status is subdivided into the traffic jam information at each main
street or each main cross point.
All individual items of information are provided with their own
classification codes. A broadcasting station transmits many
information packets with various such classification codes.
However, a receiving set designates only one or a few
classification codes. For example, a particular receiving set may
select only the information of weather forecasts, whereas another
one may select only the information relating to local traffic
status. However, it is also possible for a receiving set to change
the designation of the classification codes.
A classification code consists of a symbol signifying a
classification code and a sequence of numerals. For example, a
classification code is represented by a slash symbol "/" and ten
numerals succeeding the "/".
______________________________________ /0000010034 traffic status
at Midosuji Street /0000010100 traffic status at Pacific Street
/0012000000 general weather forecast in Japan /0012000100 weather
forecast in New York ______________________________________
where slash "/" signifies a classification code.
With regard to traffic status information, either wide-range
information or narrow-range information, e.g., at Midosuji Street
or at some spot of Midosuji Street may be designated by the
classification codes. Similarly, with regard to a weather forecast,
either whole national or local weather forecasts may be selected by
the classification codes. Also, regarding stock market prices,
either whole stock prices or a stock price of a certain corporation
may be selected. These designations are done using classification
codes.
(ii) distinction code:
This is a code annexed to each different text. The function of the
code is to distinguish different texts or equivalent texts and to
prevent two equivalent texts from being accumulated doubly at a
receiving set. Because the function of the code is to distinguish
texts, the distinction codes may be only a series of numbers.
However, another choice of distinction codes is possible, as will
be explained below.
A distinction code comprises the year, month, date, o'clock and
minute of the time when the text is drawn, the number of times of
transmission and the time of transmission. A distinction code also
consists of a symbol signifying a distinction code, e.g., a yen
symbol " " and a sequence of sixteen numerals succeeding the
symbol. " ", ".vertline." or " " is also available instead of "
".
For example, 8412041034011102 may be transmitted. This signifies
that this text has been drawn at 34 minutes past 10 o'clock on the
4th day of December, 1984, that this is the first time of
transmission and that the transmission time is 2 minutes past 11
o'clock. " " is a symbol for distinguishing it as a distinction
code.
As another example, 8412041343031705 signifies that this text has
been drawn at 43 minutes past 13 o'clock on the 4th day of
December, 1984, that this is the third time of transmission and
that the transmission time is 5 minutes past 17 o'clock.
(iii) test:
This is a part which will become voice information. A text is a
sequence of words, numerals and symbols which can be converted into
voice by a text-to-speech synthesizer. For example, "at .DELTA. the
.DELTA. midosuji street, the .DELTA. lane .DELTA. toward .DELTA.
the .DELTA. north .DELTA. is .DELTA. being jammed." This is a
sequence of the square forms of Japanese syllabary, comma, period
and an accent symbol . The sequence of words and symbols shall be
converted into voice by a text-to-speech synthesizer.
A text may be a sequence of words and symbols which consist of the
square forms of Japanese syllabary, Chinese characters, comma,
period, alphabets, pronunciation symbols, numerals, an accent
symbol and a blank symbol. In this case a word cannot be
represented by a digital signal of eight bits. However, a text may
be represented by a more restricted scope of words. For example, a
text may be constituted by the sentences consisting of the square
forms of Japanese syllabary, comma, period, alphabets, numerals, an
accent symbol and a blank symbol.
The square forms of Japanese syllabary have about 50 words. The
alphabets have 26 words, because the texts require no difference
between capital letters and small letters. The numerals have 10
words. Thus, each word or symbol can be represented by a digital
signal of seven bits, because the number of whole usable words and
symbols is less than 128 (7 bits). A word or symbol can be also
represented by a digital signal of eight bits which allows room for
increasing the number of usable words or symbols.
As another example, "we .DELTA. will .DELTA. tell .DELTA. weather
forecast. western .DELTA. japan is .DELTA. being .DELTA. covered
.DELTA. by" (the rest is omitted), where .DELTA. is a blank
symbol.
The two examples above-mentioned are the sentences originally
written in Japanese. Other examples which are originally written in
English will be explained.
"This is a weather forecast of the New York area. It will be fine
in the morning, but will rain in the afternoon."
Because the example is written in English, no accent symbols or
blank symbols are necessary. Ordinary written English thus can be
converted by a synthesizer, which will be described below.
"The Pacific Street is now under construction. If you will go to
the New York Station, pass through the East Street instead of the
Pacific Street."
So far a classification code, a distinction code and a text have
been explained. The sequence of transmission is a classification
code, a distinction code and a text, respectively, or a distinction
code, a classification code and a text, respectively.
One information packet is constructed with the three elements.
Examples will be explained below:
<example 1>: traffic status information /0000010034
8412041034011102 at .DELTA. the .DELTA. midosuji street, the
.DELTA. lane .DELTA. toward .DELTA. the .DELTA. north .DELTA. is
.DELTA. being jammed.
In this example, the classification code /0000010034 signifies that
the substance of the text relates to the traffic status information
at Midosuji Street. The distinction code signifies that the text
has been drawn at 34 minutes past 10 o'clock on the 4th day of
December, 1984, that this is the first time of transmission and
that the time of transmission is 2 minutes past 11 o'clock. The
text tells that the lane toward the north is jammed at the Midosuji
Street. Only this part shall be expressed by voice at a receiving
set.
<example 2>: weather forecast in Japan /0012000000
8412041343031705 we .DELTA. will .DELTA. tell .DELTA. weather
forecast. western .DELTA. japan is .DELTA. being .DELTA. covered
.DELTA. by (the rest is omitted).
In this example, the classification code /0012000000 signifies that
the text relates to the weather forecast. The distinction code
shows that the text has been drawn at 43 minutes past 13 o'clock on
the 4th day of December, 1984, that this is the third time of
transmission and that the time of transmission is 5 minutes past 17
o'clock.
<example 3>: weather forecast in New York /0012000100
8411030735040730 This is a weather forecast of the New York area.
It will be fine in the morning, but will rain in the afternoon.
The classification code /0012000100 signifies that the text relates
to the weather forecast in the New York area. The distinction code
shows that the text has been drawn at 35 minutes past seven o'clock
on the 3rd day of November, 1984, that this is the fourth time of
transmission and that the time of transmission is 30 minutes past 7
o'clock.
<example 4>: traffic status information /0000010100
8408050445011716 The Pacific Street is now under construction. If
you will go to the New York Station, pass through the East Street
instead of the Pacific Street.
Information packets may be simplified. Simplified versions of
information packets will be explained below.
A simplified information packet consists only of a classification
code and a text. A distinction code is omitted. For example:
<example 5>: traffic status information /0000010034 at
.DELTA. the .DELTA. midosuji .DELTA. street, the lane .DELTA.
toward .DELTA. the .DELTA. north .DELTA. is .DELTA. being
jammed.
<example 6>: weather forecast /0012000000 we .DELTA. will
.DELTA. tell .DELTA. weather .gradient. forecast. western .DELTA.
japan is .DELTA. being .DELTA. covered .DELTA. by (the rest is
omitted).
Because the simplified information packet lacks the distinction
code, the operation for drawing texts is simplified. However, this
version of information packets could not avoid double accumulation
at receiving sets if the same information packet was sent more than
once. Each information packet thus shall be sent only once in case
of this simplified broadcasting.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematical view of this invention in the case of
application to wireless broadcasting.
FIG. 2 is a schematical view of the structures of a broadcasting
station.
FIG. 3 is a schematical view of the structures of a receiving
set.
FIG. 4 is a schematical view of the simplified structures of a
broadcasting station.
FIG. 5 is a schematical view of the simplified structures of a
receiving set.
FIG. 6 is a schematical view of broadcasting areas in the case of
time-sharing broadcastings with wide broadcasting and narrow
broadcasting.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a broadcasting station(s) and receiving sets in
accordance with the present invention.
There may be a single broadcasting station (1) or there may be more
than one. If there are plural broadcasting stations, they transmit
information packets by time-sharing a common transmission
medium.
There are many receiving sets (2). A receiver (3) corresponds to
each receiving set (2). The receiver (3) can operate the receiving
set (2), but there is no need for the receiver (3) to stay near the
receiving set (2) or be in operation at all times.
A transmission medium (4) connects the broadcasting station(s) (1)
with many receiving sets (2). The transmission medium may be either
wire cables or wireless, electric waves. In the case of wire
cables, both an electric cable and an optical fiber cable are
available. In the case of the electric cable, either telephone
circuits or dedicated lines are available.
In the case of wireless transmission, a carrier wave of an adequate
frequency will be used as a transmission medium. Any frequency
between hundreds of kHz and hundreds of MHz is available for such
transmission.
FIG. 1 shows an example which uses an electric wave as a
transmission medium. The carrier wave is sent from antenna(s) (8)
of the broadcasting station(s) (1) and is received by antennas (9)
of the receiving sets (2). The detailed structures of the
broadcasting station and the receiving sets will be explained below
with reference to FIGS. 2 and 3.
FIG. 2 shows the schematic structure of a broadcasting station in
accordance with the present invention.
All information may be accumulated in a data base (22), a data base
(22') and so on. The data bases are, e.g., a data base of weather
information at the Meteorological Agency, a data base of traffic
information at police stations or a data base of stock prices at
the stockmarket. A sender gives an order for drawing sending
information from the data base to an information-drawing-device
(21).
According to the order for drawing, the information-drawing-device
(21) extracts necessary information from the data bases (22),
(22'), . . . , designates a classification code and annexes a
distinction code. Because a distinction code must include the time
of drawing the text, a first clock (23) supplies the time of
drawing to the information-drawing-device (21). The time of drawing
thus becomes a part of the distinction code.
For example, if information relating to a weather forecast shall be
sent, the information-drawing-device (21) refers to the data base
at the Meteorological Agency and obtains one or a few sentences
regarding the weather forecast. The sentences become a text. The
text will be designated with a classification code and be annexed
with a distinction code.
Because the classification code shows the substance of text, it is
designated by the data base. The nationwide weather forecast or the
local weather forecasts of certain districts have designated
classification codes. Then, the predesignated classification codes
corresponding to the substance of a text is given to the text.
However, although a distinction code consists of the year, month,
day, o'clock and minute of the time of drawing, the number of times
of transmission and the time of transmission, the
information-drawing-device (21) annexes only the time of drawing,
because other items are unknown then.
The information-drawing-device (21) draws an information packet
with a text, a classification code and a distinction code and
writes it in a sending information memory (25). Many information
packets are written into the sending information memory (25).
A text is composed of words and symbols. Words can be converted
into a digital signal of, e.g., seven bits or eight bits. Slash, ,
comma, period, .DELTA., or other symbols also can be converted into
a digital signal of, e.g., seven or eight bits. This conversion
from words to digital signals has already been standardized by the
Japanese Industrial Standard (JIS). In the case of digital signals
of eight bits, the slash "/" has been determined to be 00101111 and
" " has been determined to be 01011100. In a similar manner, words
have prescribed equivalences of digital representation.
According to the conversion rule, any information packet can be
replaced by a sequence of digital signals. Because the information
packet has been converted into a sequence of digital signals, the
sending information memory (25) can memorize the information
packet. If convenient memories with seven bits or eight bits have
been chosen, each word, symbol or numeral can be memorized by a
unit of the memory device, for it is a well-known matter to
accumulate words, etc., into a memory device in the form of a
digital signal.
After scanning the sending information memolry (25), a
memory-scanning-device (26) reads out information packets and sends
them to a sending-time-annexing-device (27). The number of times of
transmission is then added to the distinction code. The
sending-time-annexing-device (27) annexes the time of transmission
given by a second clock (24) to the distinction code. At this time
a distinction code is completed. The sending-time-annexing-device
(27) sends the completed information packet to a digital code
modulator (28). Each information packet consisting of a
classification code, a distinction code and a text is then
converted into analog signals in succession by the digital code
modulator (28).
The reason why the digital signal representative of information
packets should be converted into analog signals is that the
information packets shall be transmitted by electric (wireless)
wave in the embodiment of FIG. 2. However, in case electric wire
cables or optical fiber cables are used as transmission media, the
digital signals can be transmitted without the conversion to analog
signals.
In the case of wireless (electric wave) transmission, a carrier
wave with a certain frequency is required. The sequence of digital
signals of the information packets are modulated onto the carrier
wave by amplitude (AM) or frequency (FM) modulation of the carrier
wave. For example, the digital signal "0" may correspond to a 2100
Hz modulation wave, and the digital signal "1" may correspond to a
1300 Hz modulation wave. The length of a modulation wave may be
several tenths of a millisecond to several milliseconds. This
manner of modulation is well known, and other manners of modulation
are also available. Also, the transmission medium may be either
electric cables, optical cables or electric waves.
Voice consists of vibrations between several tons of Hz and several
thousands of Hz. In case of radio broadcasting, the amplitude (AM)
or the frequency (FM) of the carrier wave is modulated by the
vibrations. A receiving set receives the electric wave, demodulates
it and drives a speaker. Thus, the velocity for transmitting voice
information is restricted by the audibility of man as well as by
the velocity of speech in radio broadcasting.
In any case, voice is not transmitted unchanged. The words and
symbols are converted to sequences of digital representations "0"
and "1" and are transmitted in the form of digital signals. In this
invention, the words and symbols and voice information are
converted to digital signals of, e.g., eight bits, and are
transmitted by a cable or by a carrier wave modulated by the
digital signals. The velocity for transmitting the voice
information is not restricted by the audibility of man or by the
velocity of speech. High transmission velocity of this invention
enables the transmission capacity to be enlarged to a great
extent.
If voice vibrations were modulated according to pulse coded
modulation (PCM), however, it should be totally impossible to
convert the voice vibrations corresponding to a single word to a
digital signal of eight bits. Instead of voice vibration, a
sequence of words and symbols and voice information is transmitted
substantially as a digital signal. This manner of transmission
enables a restricted transmission medium to transmit a lot of
information in a short time.
In case of a wireless transmission, an electric wave with a certain
frequency is used as a carrier wave. Then the digital signals must
be converted to analog signals. For example, the conversion may be
done by changing the frequency of the modulation wave which
modulates the carrier wave. Although such a modulation converts
digital signals into analog waves, the modulation totally differs
from the A/D conversion or D/A conversion of numerical values.
The electric wave modulated by the information packets is generated
by a wireless transmitter (29) and is radiated from an antenna (8).
Because the sending information memory (25) is scanned in turn, the
accumulated information packets are transmitted in succession.
Also, each text accumulated in the sending information memory (25)
represents independent information irrelevant to the neighboring
texts. Because independent short information is transmitted in
succession, receivers need not hear the transmitted information
continuously. Continuous receiving is totally unnecessary when the
data packets are used, unlike in radio broadcasting.
The structure of a receiving set will now be explained.
Even if there is only a single broadcasting station, there are a
lot of receiving sets. A receiving set receives all information
packets but disregards unnecessary ones and accumulates only
necessary information packets. A receiver is able to hear the
accumulated information by converting the texts of information
packets into voice at a convenient time.
FIG. 3 shows the structure of a receiving set in accordance with
the present invention.
An antenna (9) catches the electric wave transmitted from the
broadcasting station. A wireless receiving device (31) tuned to the
broadcasting station receives a carrier wave of predetermined
frequency, amplifies the wave and demodulates it to obtain analog
signals corresponding to the digital signals of the information
packets. A digital code demodulator (32) then demodulates the
analog signals into the digital signals, which are the information
packets consisting of classification codes, distinction codes and
texts.
The receiver has already registered the classification code(s) of
information packets which he or she wants to hear in a
classification code memory (34) of the receiver set. A first
selector (33) thus compares the classification codes of received
information packets with the classification code(s) registered in
the classification code memory (34) in succession. If there is no
registered classification code(s) common with the classification
code of a received information packet, this information packet is
not one which the receiver wants to hear. Therefore, the selector
(33) disregards the information packet. However, if the
classification code of a received information packet coincides with
any one of the registered classification codes, the selector (33)
sends the information packet to a second selector (35).
The second selector (35) compares the distinction codes of received
information packets with the distinction codes of the information
packets accumulated in an accumulator (36) in succession. If one of
the accumulated information packets has a distinction code that is
the same as that of an already received information packet, it
means that an information packet the same as the received
information packet has been accumulated in the accumulator (36). In
this case, the received information packet is unnecessary;
therefore, the second selector (35) disregards the received
information packet because it is unnecessary to accumulate the same
text more than once.
If the accumulator (36) does not have a distinction code that is
the same as the distinction code of the received information code,
the information packet has never been accumulated in the
accumulator (36). Then the second selector (35) sends the
information packet into the accumulator (36), which memorizes the
classification code, distinction code and text of the information
packet. However, the second selector (35) compares only the parts
of the distinction code which are required to identify texts.
Namely, only the parts of the year, month, day, o'clock, and minute
of drawing the text in a distinction code are compared. Neither the
number of transmissions nor the time of transmission is compared,
because there are not two different information packets having the
same number of transmissions and the same time of transmission.
This selection is required because the same information packets are
transmitted repeatedly at different times. If two information
packets are equivalent, the numbers of transmissions and the times
of transmission must be different. Then the difference of the
number of transmissions or the times of transmission does not means
that two information packets are different.
The reason why the same information packets are repeatedly
transmitted is partly because the substance of texts need not be
changed between transmissions. It is also partly because the
receiving sets sometimes may misreceive a necessary information
packet, and it is partly because the switch of a receiving set may
be sometimes turned off when a necessary information packet is
transmitted initially.
In the following manner the accumulator (36) accumulates the
information packets with classification codes, distinction codes
and texts.
A receiver gives the receiving set an output order at his or her
convenient time by turning on some switch. According to the output
order from the receiver, a scanning device (37) reads out the texts
accumulated in the accumulator (36) in succession. Only the texts
are read out. Neither classification codes nor distinction codes
are read out.
The texts read out are sent to either or both of a visual display
(38) and a text-to-speech synthesizer (39). The visual display (38)
is an apparatus for representing information by words and symbols.
For example, a CRT (Cathode Ray Tube) display is available for this
purpose. The visual display (38) is effective for a receiver with
weak reception or under very noisy transmission circumstances.
The text-to-speech synthesizer (39), on the other hand, is a device
to convert the words and symbols of texts into voice. In case of
texts written in English, the synthesizer modules may use the
techniques of "DEC talk" of DEC corporation in the U.S.A. or "PROSE
2000" of SPEECH corporation in the U.S.A., for example. The texts
converted to voice are spoken out of a speaker (40). A receiver can
thus receive the texts by listening. The comprehension by hearing
is advantageous, for it is inconvenient for a receiver to see the
visual display, e.g., when the receiver is at work or is driving a
car.
There is no problem if a single classification code is registered
at a receiving set. No inconvenience occurs when the scanning
device (37) scans the accumulator (36), because in such a case all
voice information is relevant to other voice information. However,
if more than one classification code is registered in the receiving
set, information packets with different classification codes are
arranged randomly in the accumulator (36). Because the accumulator
(36) is being scanned in succession, the texts of different
classification codes are being spoken in turn. It is uncomfortable,
therefore, because the speech lacks coherence. Furthermore, even if
a receiver has registered more than one classification code, the
receiver sometimes may want to hear only the texts with a certain
classification code. In this case it is desirable to improve the
receiving set. In the improved receiving set, the receiver is able
to designate a classification code among the plural registered
classification codes by specifying the output order. When the
receiver gives the output order as well as the designation order of
a single classification code, for example, the scanning device (37)
reads out only the texts with the designated code. Thus, the
receiver hears only the texts with the same classification
code.
As mentioned before, another simplified form of an information
packet is possible in this invention. In the simplified form, an
information packet consists of a classification code and a text
only. A distinction code is omitted. Each information packet thus
is sent only once.
This simplified method for transmitting voice information in
accordance with the invention will be explained with reference to
FIG. 4 and FIG. 5.
FIG. 4 shows the structure of a broadcasting station which lacks
the clocks (23) and (24) and the sending-time-annexing-device (27)
in FIG. 2. All information is accumulated in data bases (22),
(22'), . . . , and so on as previously, and as before, a sender
gives an order for drawing sending information to an
information-drawing-device (21). According to the order for
drawing, the information-drawing-device (21) extracts necessary
information from the data bases (22), (22'), . . . and designates a
classification code. Because the classification code shows the
substance of the text, it will be designated according to the
nature of the data base from which the text has been extracted. The
information-drawing-device (21) completes an information packet
only with a text and a classification code and writes it in sending
information memory (25). Many simplified information packets may
thus be written into the sending information memory (25).
A text is composed with words (including numerals) and symbols. The
text can be converted into a digital signal of, e.g., seven bits or
eight bits according to the conversion rule. In the data bases the
words and symbols have been written as a digital signal, and
according to the conversion rule, any information packet can be
replaced by a sequence of digital signals.
After scanning the sending information memory (25), a
memory-scanning-device (26) reads out information packets and sends
them to a digital code modulator (28). Each information packet
consisting of a classification code and a text is converted into
analog signals in succession by the digital code modulator (28). A
carrier wave with a predetermined frequency then is modulated by
the analog signals which correspond to the information packet. A
wireless transmitter (29) radiates the strong carrier wave
modulated by the information packet from an antenna (8).
FIG. 5 shows the structure of a simplified receiving set.
An antenna (9) receives the electric wave transmitted from the
broadcasting station. A wireless receiving device (31) chooses a
carrier wave of a predetermined frequency, amplifies the wave and
obtains analog signals, the carrier wave corresponding to that
modulated by the digital signals representing the information
packets. A digital code demodulator (32) then demodulates the
analog signals into the digital signals representing the
information packets. As noted above, the information packet
consists only of a classification code and a text.
The receiver has already registered the classification code(s) of
the information packet which the receiver wants to hear in a
classification code memory (34). A selector (33) compares the
classification codes of received information packets with the
classification code(s) registered in the classification code memory
(34) in succession. If there is no registered classification
code(s) common with the classification code of a received
information packet, the selector (33) disregards the information
packet. However, if the classification code of a received
information packet coincides with any one of the registered
classification codes, the selector (33) sends the information
packet to an accumulator (36). The accumulator (36) accumulates the
information packets with classification codes and texts in
succession.
A receiver gives the receiving set an output order at a convenient
time by turning on some switch. According to the output order from
the receiver, a scanning device (37) then reads out the texts
accumulated in the accumulator (36) in succession.
The texts read out are sent to either or both of a visual display
(38) and a text-to-speech synthesizer (39). As noted above, the
visual display (38) is an apparatus for representing information by
words and symbols. The text-to-speech synthesizer (39) is a device
for converting the words and symbols of text into voice which is
heard from speaker (40).
In this invention, various kinds of voice information are
transmitted discontinuously as information packets. All information
packets are independent, and an information packet is irrelevant
with respect to the neighboring ones.
Each receiving set accumulates some of the information packets, and
a receiver can hear the voice information at any time after the
transmission. Also, there is no requirement to transmit voice
information continuously without pause from a broadcasting station.
Therefore, this invention enables more than one broadcasting
station to transmit different kinds of information by sharing the
transmitting time. This is called time-sharing broadcasting.
FIG. 6 shows the broadcasting areas in the case of time-sharing
broadcasting for wide broadcasting and narrow broadcasting.
A unit period of time is divided. For example, a transmitting time
unit of one minute is divided into a 45 seconds subperiod and a 15
seconds subperiod. For each earlier 45 seconds subperiod, a big
broadcasting station transmits nation-wide programs to a wide
broadcasting area (A) with a strong electric wave. For each
subsequent 15 seconds subperiod, small local broadcasting stations
may transmit local information for the small areas B.sub.1, B.sub.2
. . . from many automatic transmitters by weak electric waves. The
electric waves propagate only within the small areas B.sub.1,
B.sub.2, . . . . The information may thus represent local
information such as traffic status of streets or cross points. For
example, the automatic transmitters may be located at cross points
51, 52, . . . of streets. They radiate electric waves without an
operator.
There may be two broadcasting stations with the same carrier wave
in some areas. Furthermore, more than two broadcasting stations may
be installed in the same areas. However, because the frequency of
the carrier wave is common, the plural broadcasting stations
require no more than one frequency.
The advantages of the present invention now will be explained.
(1) This invention enables a receiver to hear only necessary voice
information by an automatic selection of the receiving set.
Unnecessary information is not heard so that the receiver can save
time and alleviate the necessity of listening to undesired
information.
(2) A receiver can hear only necessary information at an arbitrary
and convenient time.
(3) Without manual operation, the broadcasting station can convert
the information stored in computers to information packets and can
transmit them automatically. Input of information requires neither
manual operations nor speeches by announcers before microphones.
The broadcasting processes thus can be automated, because nobody
need read aloud texts.
(4) Enormous amounts of information can be transmitted in a short
time, because the broadcasting station transmits not voices but
digital data which is later converted to voices.
If voice vibration is transmitted as PCM (Pulse Code Modulation)
signals, the amount of information is 56 kbit/sec in case of a
normal rate of speech. This is a large amount of information. It is
available because the voice vibration is directly sampled in a PCM
manner.
In this invention, the amount of information is about 80 bits/sec
in the case of a normal rate of speech, because each word or symbol
is transmitted as a digital signal of seven or eight bits.
Moreover, this invention requires a very small information
capacity, about one seven-hundredth of that of the PCM voice
transmission.
Namely, this invention enables the broadcasting stations to
transmit much information in a short time. High efficiency of
transmission is thus an advantage of this invention, and this
invention is greatly superior to radio broadcasts regarding the
efficiency of transmission.
(5) Because much information can be transmitted, the transmitted
information can be affluent and varied in substance.
(6) Plural broadcasting stations can use carrier waves with the
same frequency by sharing transmitting time.
(7) What selects the substance of information is not a broadcasting
station but receiving sets. A broadcasting station need not select
information to be transmitted. This fact alleviates the duty of a
broadcasting station, and the programs for transmission of a
broadcasting station are greatly simplified.
(8) If information packets include distinction codes, the
broadcasting station may transmit the same text more than once.
Receiving sets thus have several chances to receive each
information packet. This is particularly beneficial if the
receiving set exists in an area with a low intensity of electric
wave, for if the receiving set is out of order temporarily or if an
electric wave is perturbed by thunder, the receiving set may fail
to receive the first transmission of an information packet. In
these cases, the receiving set can receive all necessary
information during a later transmission.
* * * * *